An exhaust gas recirculation device (EGR device) is known in which the combustion temperature of an air-fuel mixture in an engine is lowered in order to improve the exhaust gas composition by mixing part of the exhaust with the intake air.
This exhaust gas recirculation device comprises an EGR passage connecting an exhaust passage with an intake passage of the engine, an EGR control valve which is provided in the EGR passage for controlling an EGR flowrate, and an actuator which drives the EGR control valve by a negative pressure in the intake passage.
As high temperature exhaust gas circulates through the EGR passage and EGR control valve, they easily reach a high temperature. In this regard, Jikkai Hei 7-42423 published by the Japanese Patent Office in 1995 discloses providing a heat blocking member near the EGR passage and EGR control valve so that the heat produced by the EGR device does not affect parts located in the vicinity of the EGR device such as signal wires or hoses.
However, this heat blocking member or the like may be forgotten to be reinstalled after removing it for the repair of the engine or peripheral devices, and such a mistake could conceivably occur even in a manufacturing plant.